So, I finally got my jeep street legal, and I took her to work tonight delivering pizzas. It was about 80 degrees outside today, and my jeep overheated, bad. I somehow forgot to check the coolant with everything else I have done to the jeep. So I let it cool a bit, and put about a gallon and a half of water in it, drove it maybe a mile to advanced auto, where it was tacked again, overheating. I let it cool all the way here, and put 2 gallong of coolant in it. This is a total of 3 and a half gallons. Coolant tank thing still empty. I ran out of cash and still needed to get my car for work. Drove it home, about 7 miles, and stayed at 210. That was awesome. However, i am concerned about how much i put in. It was gurgleing at the thermostat area. I just want to check to make sure I don't have a blown head gasket since it is not leaking...

This is an 88 Cherokee Loredo, Automatic.

 

Ya'know 50/50 mix is the goal, normally. Don't top the expansion bottle! I do mine about 1/2. Just keep it there while it warms up, till after the thermostat opens. Then check it cold. Water conducts/conveys heat better than coolant is why it's 1/2 & 1/2. 100% ethylene glycol won't carry as much heat.

 

right. but my question is how much coolant does the whole system hold?

 

i dont think it holds 31/2 gallons mine sure doesnt ive never had it 31/2 gallons low thats not low thats f'ing empty

 

I usually fill the overflow bottle about halfway, then let the engine warm up with the cap off. The thermostat opens after a little (revving helps) and sucks some down. Then I turn it off, pour a little more in, and repeat the process. This gets all the air out of the system. I believe it takes about 2 coolant jugs to fill to that point. More likely 3 to full capacity, but I leave it around halfway. Keep in mind thats with the block also full of coolant, which probably adds another gallon or so. I say 4 gallons at the most to fill up the complete system. If the bottle remains at halfway, keep it there. Also, if it is mostly straight coolant, drain some from the little plug on the side of the radiator and into a coolant pan. Hook a hose up to the end of the drain and route it under the jeep somewhere where you can catch it. Then replace with water. if you have a coolant gauge, test it. They look like a turkey baster with some discs inside that measure the density of the coolant. I flushed my system a few times, I'm becoming a pro with the undesirable renix coolant system.

 

lol XJ89. Yeah, mine is 50/50, i just put some water in it to get me to advanced (closest place with coolant) I have to see whats up. The oil doesnt seem to be milky, which is what i was expecting, and there is no leak, so i will have to check it out this weekend.

 

Something happening u shouldn't need 3 1/2 gallons

 

Yeah... That is what I am figuring... Eck. But, To be honest, I cannot even begin to guess what the PO did to this thing. I mean, this jeep was rough. It did pass inspection, finally, after pouring about 3 grand in it. First time really driving her, and i made it like 1 and a half hours into my shift. lol. I am fearing the Head Gasket. Luckily I can do that, but Do I want to? Not Really. lol.

 

as much money as youve sank into it look into upgradeing to newer cooling system with radiator cap its under 200 dollars to do and well worth the effort ,renix closed cooling system will be a constant pain in the ***...jm2cw

 

My Renix cooling system works just fine. I had to replace the bottle and cap about 3 years ago due to age/splitting of the bottle. It has never overheated.

BTW, Cherokee cooling system takes about 2 gallons total +/-.

 

1) Capacity should be on my site, in the Tech section.

2) Not a damned thing wrong with the "Closed" coolant system inherently. If it's so bad, why are OEMs moving toward it? Change the coolant bottle every ten years or so, change the cap every five years or so (like any other pressure cap,) and flush the system every other year.

3) The only real "problem" I can think of with the closed system - in most applications, not just the XJ & MJ - is that you can collect an air pocket behind the thermostat. This is a normal occurrence - and also easy to prevent. Simply drill two 1/16" (or so) holes in the thermostat flange, 180* apart, far enough in that they won't get covered by housing or gasket. Install with one hole at 12:00 and the other at 6:00. The system will now purge itself freely of entrained air - both on filling (a common problem,) or in the event of overheating (also a common problem - with anything.) Fill the system after a service, let it idle for 10-15 minutes, top off. Monitor temperatures (which you should do anyhow,) and top off at 1-2 days' service.

NB: "Cold" coolant should never be added to a "hot" engine - unless you add it slowly, and with the engine running! It is possible that you can crack a casting with the "cold spot" you'd create this way, and I have seen it happen to people! Pour it in at a trickle with the engine idling, and you'll be okeh.

This applies to any liquid-cooled engine!

I've had five RENIX rigs to date - the one that ran hottest was the one that had been converted to the "open" system (done before I bought it. I was toying with converting it back.)

The only real "fault" with RENIX radiators is that they tend to lose heat transfer ability (I'm not sure why) around 150-180kmiles. This is usually when the system is converted - the problem is inadvertently repaired in the process of the conversion (even the Jeep wrenches at the local dealer don't use OEM radiators to replace RENIX OEM units - they use Modine aftermarket, as they hold up better than the Modine OEM. No-one knows why. I'll either use Modine or Performance radiator - this was before I found out about CSF units, but reports from the field on them are consistently good as well.)

A bottle of Water Wetter in the coolant of any liquid-cooled vehicle won't go amiss, either.

 

Alrighty. Now, the other question. My fan as no shroud, and therefore not really puuling the air through the Radiator. I guess it doesnt matter much, considering that if I poured 3 1/2 gallons in, I clearly have other issues...
But how important is the shroud for cooling?

 

Pretty important normally over looked with the cooling system

 

It needs the shroud to effectively suck air through when you are not cruzen. On the freeway, it maters not. Stopped in traffic, or climbing a hill at low speed, it maters plenty!

You know, one quick easy way to find a bad, bad, head gasket is to power-brake it with the cap off and look for bubbles, (or a geyser!)

Another is to sniff the coolant with a smog tester for hydrocarbons.

 

A fan shroud is much more important than you might think. To answer the amount of coolant in the Renix coolant system should be roughly 1.5 to 2 gallons of 50/50 coolant. People complain all the time about the Renix coolant system but I have to agree with 5-90 on this one. It's a perfectly normal system you just have to know how to fill it. I squeeze the radiator hoses when filling the tank up. This allows the system to purge and gets rid of the air quicker. Several days after I fill the system up with coolant I check the coolant level before I drive it. After a couple days it shouldn't require any more coolant.

To adress the fan should think of it as if the fan does not have a shroud the air just cirulates around the fan and actually doee not push new air through it.

The biggest concern is what heated up when the engine was hot. Getting engines hot completly ruins them. Listen for any issues coming from the motor. If the coolant isn't leaking out anywhere or coming out of the vent cap on the coolant bottle then I would assume all that coolant is going into the engine. I would highly recomend you drain the oil and look for oil mixed in with coolant. If so you need to pull the head.

Be a true Jeep driver and carry an extra gallon of coolant with you where ever you go

Good luck on it man